HIT Man

It's an ominous sign and finding in medicine. A patient needs to have clots stopped so the clots don't do damage to end organs...stroke in the brain, infarction in the heart, thrombosis to any other organ that needs a blood supply...so you give heparin, a medicine used to stop the blood from clotting.

And then it happens...a rapid fall in the number of platelets with more clotting than even before you gave the heparin. The patient has HIT...Heparin Induced Thrombocyto(platelets)-penia(too few). The heparin has bound with PF4, joined an IgG, formed a complex and then attacks the platelet...marking it for destruction in the spleen or activating it to clot...what you don't want in the first place.

It's essentially an allergic reaction to the heparin and a good thing to know before you go into the hospital as a patient. It's not a good idea to get HIT!